JP2020011525A - Brake fluid pressure control device - Google Patents

Abstract

To provide a brake fluid pressure control device which is capable of restraining residence of air bubble in a discharge side of a pump.SOLUTION: The brake fluid pressure control device comprises a housing, a motor which is equipped in the housing, and a plurality of pump elements which are equipped in a recess part formed on a side surface of the housing and are driven by the motor. The pump elements each comprise a suction valve which intakes a brake fluid into a pump chamber, a discharge valve which discharges the brake fluid from the pump chamber, and a flow channel formation member which is disposed on a discharge side of the discharge valve. The flow channel formation member comprises a spring chamber which accommodates a spring urging a valve body of the discharge valve in a valve closing direction, and a passage which comes into communication with the spring chamber and an outside surface of the flow channel formation member. Passages of the respective flow channel formation members of the plurality of pump elements are connected to the outside surface by extending from a position containing a vertical direction uppermost part of the spring chamber to an upward direction.SELECTED DRAWING: Figure 3

Description

  The present invention relates to a brake fluid pressure control device.

  2. Description of the Related Art Conventionally, there has been known a brake fluid pressure control device that performs a brake control by controlling a fluid pressure of a brake fluid supplied to a brake unit of a wheel by a hydraulic circuit. The brake fluid pressure control device includes a fluid pressure unit having a fluid pressure circuit and a control device.

  The hydraulic unit includes a control valve that can be freely opened and closed, a pump that operates in conjunction with the control valve, an electric motor that drives the pump, and the like. The brake fluid pressure control device is electronically controlled and operates automatically, and controls the braking force generated on the wheels by increasing or decreasing the fluid pressure in the brake fluid pressure circuit.

  The pump of the hydraulic unit is mounted in a recess formed in the outer surface of the housing. An eccentric cam is provided on the motor shaft of the electric motor, and the piston of the pump reciprocates as the eccentric cam rotates. In this way, the pump discharges the brake fluid in the brake hydraulic circuit (for example, see Patent Document 1).

JP 2013-071491 A

  FIG. 7 is an axial cross-sectional view including the discharge valve 180 of the pump assembly, and FIG. 8 is a schematic diagram illustrating the housing 130 and the cover member 185 in a II-II cross section of FIG.

  As shown in FIGS. 7 and 8, the pump assembly mounted in the recess of the housing 130 includes a cover member 185 fixed by caulking by the edge of the opening of the recess. The cover member 185 has a spring chamber 185a that houses a spring 183 that urges the valve element 181 of the discharge valve 180, and a passage 187 that guides the discharged brake fluid to the oil passage 111b.

  Here, air may be mixed in the brake hydraulic circuit. When the cover member 185 is arranged so that the passage 187 extends downward in the vertical direction from the spring chamber 185a, bubbles contained in the brake fluid discharged from the discharge valve 180 are likely to stay in the spring chamber 185a. If air bubbles stay in the spring chamber 185a, the operating noise of the brake fluid pressure control device may increase.

  The present invention has been made in view of the above problems, and provides a brake fluid pressure control device capable of suppressing the accumulation of bubbles on the discharge side of a pump.

  According to an aspect of the present invention, there is provided a brake fluid pressure control device that controls a fluid pressure of a brake fluid pressure circuit, a housing in which a brake fluid flow path is formed, and a motor mounted in the housing. A plurality of pump elements mounted in a recess formed in a side surface of the housing and driven by a motor, wherein the pump element has a suction valve that sucks brake fluid into a pump chamber and a discharge valve that discharges brake fluid from the pump chamber. A valve, and a flow path forming member disposed on the discharge side of the discharge valve, wherein the flow path forming member includes a spring chamber that houses a spring that biases a valve body of the discharge valve in a valve closing direction, and a spring chamber. A passage communicating with the outer surface of the flow path forming member, wherein the path of each flow path forming member of the plurality of pump elements extends upward from a position including the vertical uppermost portion of the spring chamber. Brake fluid pressure control apparatus characterized by being connected to the outer surface is provided.

  As described above, according to the present invention, the retention of bubbles on the discharge side of the pump can be suppressed.

It is a perspective view showing a brake fluid pressure control device concerning an embodiment of the invention. It is sectional drawing which shows the state in which the pump element was mounted in the recessed part of the housing. It is sectional drawing which expands and shows the discharge valve and cover member of a pump element. It is explanatory drawing which shows a housing and a cover member typically. It is the schematic diagram which looked at the cover member in the axial direction. It is explanatory drawing which shows the inclination angle of a passage. FIG. 3 is an axial sectional view including a discharge valve of a pump assembly as a reference example. It is a schematic diagram which shows the housing and cover member as a reference example.

  Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. In the specification and the drawings, components having substantially the same functional configuration are denoted by the same reference numerals, and redundant description will be omitted.

<1. Brake fluid pressure control device>
An overall configuration example of the brake fluid pressure control device according to the present embodiment will be described with reference to FIG. FIG. 1 is a perspective view showing an example of the brake fluid pressure control device 20. The brake fluid pressure control device 20 includes a fluid pressure unit 110 and an ECU 140.

  The brake fluid pressure control device 20 is provided in a brake system of a vehicle, and controls a braking force of each wheel. The brake fluid pressure control device 20 shown in FIG. 1 is a device provided in a brake system for a four-wheeled vehicle, and is configured to be able to execute ESP (Electronic Stability Program) control.

  The hydraulic unit 110 includes a housing 130. The housing 130 includes two connection ports 91a and 91b connected to two pressure chambers of a master cylinder (not shown), and four connection ports 93a to 93d connected to wheel cylinders of each wheel (not shown).

  An oil passage is formed inside the housing 130, a first hydraulic circuit that connects one connection port 91a and two connection ports 93a and 93b, and one connection port 91b and two connection ports 93c, A second hydraulic circuit for connecting the second hydraulic circuit 93d is formed.

  Each of the first hydraulic circuit and the second hydraulic circuit includes a plurality of control valves, an accumulator 71, and a pump element 44. The plurality of control valves, the accumulator 71, and the pump element 44 are mounted in recesses formed on the outer surface of the housing 130, and intervene in the oil passage.

  The plurality of control valves include a circuit control valve, a suction control valve, a pressure increasing valve, and a pressure reducing valve. The pressure increasing valve and the pressure reducing valve are provided in an oil passage that communicates with a wheel cylinder of each wheel. The circuit control valve communicates or shuts off between the master cylinder and the booster valve. The suction control valve communicates or shuts off between the master cylinder and the suction side of the pump element 44.

  The pressure increasing valve is capable of linear control, and increases the wheel cylinder pressure while continuously adjusting the flow rate of the brake fluid from the master cylinder and the circuit control valve side to the wheel cylinder side of each wheel. The pressure reducing valve is a control valve that can be switched between fully open and fully closed, and reduces the wheel cylinder pressure by supplying the brake fluid supplied to the wheel cylinder of each wheel to the accumulator 71 in the open state.

  The accumulator 71 accumulates or discharges the brake fluid while changing the volume in accordance with the pressure of the brake fluid supplied via the pressure reducing valve.

  The pump element 44 operates by driving a motor 96 to discharge the brake fluid. The suction side of the pump element 44 is connected to the accumulator 71 via a check valve. The check valve enables the movement of the brake fluid from the accumulator 71 side to the suction side of the pump element 44, but disables the movement of the brake fluid in the opposite direction. The discharge side of the pump element 44 is connected to an oil passage connecting the circuit control valve and the pressure increasing valve.

  As shown in FIG. 1, the motor 96 is mounted on one side surface 130a of the housing 130. The pump element 44 is mounted on a side surface 130c that is vertically continuous from the side surface 130a. The other pump element 44 (not shown in FIG. 1) is mounted on a side surface which is vertically continuous from the side surface 130a and is located at the back of the side surface 130c.

  Two accumulators 71 are mounted on a lower surface 130b that is vertically continuous from both a side surface 130a on which the motor 96 is mounted and a side surface 130c on which the pump element 44 is mounted (only one is shown in FIG. 1).

  A circuit control valve, a suction control valve, a pressure increasing valve, and a pressure reducing valve are mounted on the rear surface of the side surface 130a to which the motor 96 is mounted. The ECU 140 is mounted on the rear side of the side surface 130a to which the motor 96 is mounted.

  The ECU 140 includes a plurality of control valves and an electronic control board that controls driving of the motor 96 and the like. The ECU 140 controls the opening and closing of a plurality of control valves during the operation of the ESP to control the braking force of the left and right front and rear wheels.

  The hydraulic unit 110 may further include a pressure sensor, a damper, and the like, in addition to the above components.

<3. Pump element>
Next, the pump element 44 provided in the brake fluid pressure control device 20 according to the present embodiment will be described in detail.

(Configuration example of pump element)
FIG. 2 is a cross-sectional view showing a state where the pump element 44 is mounted in the recess 131 of the housing 130. In the following description, the direction in which the piston structure 150 of the pump element 44 is disposed may be referred to as a front end side, and the opposite direction may be referred to as a rear end side.

  A concave portion 131 in which the pump element 44 is accommodated is formed on one side surface 130c of the housing 130. The concave portion 131 is a stepped hole formed in a substantially cylindrical shape extending in a direction orthogonal to the direction of the axis Am of the motor shaft 96a. One end of the recess 131 opens to the side surface 130c of the housing 130, and the other end opens to a space where the motor shaft 96a is arranged.

  Two oil passages 111a and 111b are connected to the recess 131 from a direction intersecting the direction of the axis A of the recess 131. The oil passage 111 a is a flow passage that guides the brake fluid to the pump element 44. The oil passage 111b is a flow passage through which the brake fluid discharged from the pump element 44 flows.

  The pump element 44 has a piston structure 150 abutting on an eccentric bearing 125 supported eccentrically on the motor shaft 96a. In the pump element 44, the piston structure 150 reciprocates in the direction of the axis A by the rotation of the eccentric bearing 125, and sucks and discharges the brake fluid.

  The pump element 44 has a piston structure 150, a spring 159, a housing member 160, a suction valve 170, a discharge valve 180, and a cover member 185. In the present embodiment, the cover member 185 has a function as a flow path forming member.

  The piston structure 150 reciprocates in a direction perpendicular to the direction of the axis Am of the motor shaft 96a with the rotation of the eccentric bearing 125. A part on the rear end side of the piston structure 150 is housed in the housing member 160. The housing member 160 is, for example, a member that is pressed into the recess 131 and fixed by the cover member 185.

  The housing member 160 has therein a housing chamber 161 which is an axial hole formed along the direction of the axis A. The accommodation room 161 has a function as a pump room. That is, the brake fluid flowing into the storage chamber 161 via the suction valve 170 is pressurized and discharged via the discharge valve 180.

  The accommodation chamber 161 is opened to the front end side, and the rear end of the piston structure 150 is slidably inserted from the front end side. A spring 159 is accommodated in the accommodation room 161. The spring 159 is an embodiment of an urging member, and is held in a compressed state between the piston structure 150 and the housing member 160 to urge the piston structure 150 toward the distal end.

  A guide member 167 that slidably holds the piston structure 150 is attached to the distal end of the housing member 160. One or more passage holes 167a are formed in the peripheral surface of the guide member 167. The passage hole 167a communicates the outside and the inside of the guide member 167.

  In the present embodiment, the piston structure 150 includes a tip member 151, an intermediate member 153, and a base 155.

  The tip member 151 is a substantially columnar member having a tip portion formed in a convex curved surface. The tip member 151 is a portion that comes into contact with an eccentric bearing 125 eccentrically supported by the motor shaft 96 a of the motor 96, and a rear end portion is held by the intermediate member 153. The tip member 151 is slidable on the guide member 167 and the housing 130.

  Further, an annular seal member 169 is provided between the distal end member 151 and the concave portion 131 on the distal end side of the guide member 167.

  The intermediate member 153 is a hollow substantially cylindrical member having axial holes opened at both ends in the direction of the axis A. The front end member 151 is held at the front end of the intermediate member 153, and the rear end of the intermediate member 153 is held by the base 155.

  One or more through holes 153a are formed in the peripheral surface of the intermediate member 153. The passage hole 153a communicates the outside and the inside of the intermediate member 153.

  The base 155 is a hollow, substantially cylindrical member having a distal end side holding the intermediate member 153 formed as an open end. The base 155 has a sliding portion 156 that can slide on the inner peripheral surface of the storage chamber 161 of the storage member 160.

  One or more through holes 155a are formed on the peripheral surface of the base 155 on the rear end side of the sliding portion 156. The passage hole 155a communicates between the outside and the inside of the base 155. Inside the base 155, a valve body 171 and a spring 173 constituting the suction valve 170 are housed.

  The spring 173 is held between the valve body 171 and the base 155 in a compressed state and urges the valve body 171 toward the intermediate member 153. The peripheral portion of the opening on the rear end side of the axial hole of the intermediate member 153 is a seat portion with which the valve body 171 contacts.

  A tapered hole 163 is formed on the rear end surface of the housing member 160. The tapered hole 163 communicates the outside of the rear end side of the housing member 160 with the housing chamber 161. The tapered hole 163 is formed so as to increase in diameter toward the rear end side. The tapered hole 163 becomes a seat portion with which the valve element 181 of the discharge valve 180 contacts.

  The discharge valve 180 includes a valve body 181, a housing member 160, a spring 183, and a cover member 185. The cover member 185 has a function of fixing the pump element 44. The cover member 185 is attached to the housing 130 in a liquid-tight manner so that the brake fluid does not leak from the recess 131.

  In the present embodiment, the cover member 185 is fitted to the rear end of the housing member 160 and is caulked and fixed by the opening edge of the recess 131. The cover member 185 has a spring chamber 185a and a passage 187.

  The spring chamber 185a is a cylindrical space that extends in the direction of the axis A and opens to the front end side. A spring 183 is housed in the spring chamber 185a. The spring 183 is held in a compressed state between the valve body 181 and the bottom surface of the spring chamber 185a. The spring 183 biases the valve body 181 toward the tapered hole 163. That is, the spring 183 biases the valve body 181 in the valve closing direction of the discharge valve 180.

  The passage 187 communicates the spring chamber 185a with the outer surface of the cover member 185, and guides the brake fluid discharged from the discharge valve 180 to the oil passage 111b. In the present embodiment, one end of the passage 187 opens on the outer peripheral surface of the cover member 185, and a liquid chamber 133 is formed at the opening position of the passage 187. The brake fluid is guided to the oil passage 111b via the fluid chamber 133.

  In the pump element 44 configured as described above, when the piston structure 150 moves to the distal end side with the rotation of the eccentric bearing 125 driven by the motor 96, the capacity of the storage chamber 161 increases and the volume in the storage chamber 161 is increased. Hydraulic pressure drops. At this time, the discharge valve 180 is closed, while the suction valve 170 is opened. As a result, the brake fluid flows into the storage chamber 161.

  On the other hand, when the piston structure 150 moves to the rear end side with the rotation of the eccentric bearing 125 driven by the motor 96, the volume of the storage chamber 161 is reduced and the hydraulic pressure of the storage chamber 161 increases. At this time, the suction valve 170 is closed, while the discharge valve 180 is opened. As a result, the brake fluid is discharged through the discharge valve 180. The discharged brake fluid flows out to the oil passage 111b via the passage 187 of the cover member 185 and the liquid chamber 133. The pump element 44 repeats the suction and discharge of the brake fluid as described above with the rotation of the motor 96.

(Arrangement of passage)
Next, the arrangement of the passage 187 formed in the cover member 185 will be described with reference to FIGS. Hereinafter, the passage 187 of the cover member 185 of one pump element 44 will be described. However, in the brake fluid pressure control device 20 according to the present embodiment, the passages 187 of the cover members 185 of all pump elements 44 are similarly arranged. .

  FIG. 3 is an enlarged sectional view showing the discharge valve 180 and the cover member 185 of the pump element 44. FIG. 4 is an explanatory diagram schematically showing the housing 130 and the cover member 185 at the position of the II section in FIG. The vertical direction in FIGS. 3 and 4 corresponds to the vertical direction in the vertical direction.

  In the brake fluid pressure control device 20 according to the present embodiment, the passage 187 formed in the cover member 185 extends upward from a position including the uppermost portion P in the vertical direction of the spring chamber 185a and is connected to the outer surface of the cover member 185. . In the example shown in FIGS. 3 and 4, the passage 187 extends upward along the vertical direction from a position including the vertical uppermost portion P of the spring chamber 185a.

  Therefore, when the cover member 185 is viewed in the axial direction, the uppermost portion P in the vertical direction of the spring chamber 185a is located between the left and right boundary lines L1 and L2 of the passage 187. Therefore, when air is mixed in the hydraulic circuit, the air discharged together with the brake fluid via the discharge valve 180 is discharged to the liquid chamber 133 without staying in the spring chamber 185a. Therefore, at the time of operation of the brake fluid pressure control device 20, it is possible to suppress an increase in the operation noise due to the bubbles remaining in the spring chamber 185a.

  The direction in which the passage 187 extends from the spring chamber 185a is not limited to vertically upward. When the cover member 185 is viewed in the axial direction, as long as the vertical uppermost portion P of the spring chamber 185a is located between the left and right boundary lines L1 and L2 of the passage 187, the passage 187 may be moved from the upper right to the left or right. Or it may be inclined to one side. In this case, the condition that the vertical uppermost portion P of the spring chamber 185a is located between the left and right boundary lines L1 and L2 of the passage 187 means that one of the boundary lines L1 and L2 intersects the vertical uppermost portion P. Including.

  FIG. 5 is a schematic view of the cover member 185 viewed in the axial direction. The passage 187 shown in FIG. 5 is such that the passage 187 is inclined to the left as much as possible such that the uppermost portion P in the vertical direction of the spring chamber 185a is located between the left and right boundary lines L1 and L2 of the passage 187 (inclination angle = θ). ).

  The intersection between one boundary line L2 of the passage 187 and the spring chamber 185a is located above the intersection between the other boundary line L1 and the spring chamber 185a, and the intersection between the boundary line L2 and the spring chamber 185a is the spring room 185a. Of the uppermost portion P in the vertical direction. Therefore, when the air moves to the uppermost portion P in the vertical direction of the spring chamber 185a, the air is released upward through the passage 187.

  Similarly, the passage 187 ′ shown in FIG. 5 is such that the passage 187 is tilted to the right as much as possible so that the uppermost portion P in the vertical direction of the spring chamber 185a is located between the left and right boundary lines L1 and L2 of the passage 187 ( 4 shows a path with an inclination angle of -θ).

  The intersection between one boundary line L1 'of the passage 187' and the spring chamber 185a is located above the intersection between the other boundary line L2 'and the spring chamber 185a, and the intersection between the boundary line L1' and the spring chamber 185a. Coincides with the vertical uppermost portion P of the spring chamber 185a. Therefore, when the air moves to the uppermost portion P in the vertical direction of the spring chamber 185a, the air is released upward through the passage 187.

When the center line C of the passage 187 overlaps the axis A of the spring chamber 185a, the passage 187 extends so that the width W of the passage 187, the radius r of the spring chamber 185a, and the inclination angle θ of the passage 187 satisfy the following expression (1). You may.

で示される。 That is, as shown in FIG. 6, the inclination angle θ when the passage 187 is inclined to the left as much as possible so that the vertical uppermost portion P of the spring chamber 185a is located between the left and right boundary lines L1 and L2 of the passage 187. Is

Indicated by

  For this reason, when the above expression (1) is satisfied, the vertical uppermost portion P of the spring chamber 185a is located between the left and right boundary lines L1 and L2 of the passage 187, and the uppermost portion of the spring chamber 185a. Can be released upward through the passage 187.

  As described above, according to the brake fluid pressure control device 20 according to the present embodiment, the spring chamber 185 a and the cover member 185 are provided on the cover members 185 disposed on the discharge sides of the discharge valves 180 of all the pump elements 44. A passage 187 communicating with the outer surface of the spring chamber 185 extends upward from a position including the uppermost portion P in the vertical direction of the spring chamber 185a and is connected to the outer surface.

  Therefore, even when air is mixed in the hydraulic circuit, it is possible to prevent the air discharged together with the brake fluid discharged from the discharge valve 180 from staying inside the spring chamber 185a. it can. Therefore, it is possible to suppress an increase in the operating noise of the brake fluid pressure control device 20.

  As described above, the preferred embodiments of the present invention have been described in detail with reference to the accompanying drawings, but the present invention is not limited to such examples. It is apparent that those skilled in the art to which the present invention pertains can conceive various changes or modifications within the scope of the technical idea described in the appended claims. It is understood that these also belong to the technical scope of the present invention.

  Further, in the above embodiment, the brake fluid pressure control device mounted on a four-wheeled vehicle is described as an example, but the present invention is not limited to this example, and the brake fluid pressure control device mounted on another vehicle is described. It may be a pressure control device.

  Further, in the above embodiment, the example in which the cover member 185 for fixing the pump element 44 to the concave portion 131 of the housing 130 is a flow path forming member has been described, but the present invention is not limited to this example. The present invention can be applied to any brake fluid pressure control device provided with a member disposed on the discharge side of the discharge valve of the pump element and having a passage connecting the spring chamber and the outer surface of the member. it can.

  In the above embodiment, the oil passage 111b into which the brake fluid discharged from the pump element 44 flows extends upward from the recess 131, but the present invention is not limited to this example. The oil passage 111b may extend laterally or downward from the liquid chamber 133.

  Further, in the above embodiment, the cover member 185 has one passage 187, but the present invention is not limited to this example. When the flow path forming member (cover member) includes a plurality of passages, at least one passage extends upward from a position including the uppermost portion in the vertical direction of the spring chamber and is connected to the outer surface, so that the spring chamber has The retention of bubbles can be suppressed.

Reference numeral 20: brake hydraulic pressure control device, 44: pump element, 96: motor, 110: hydraulic unit, 125: eccentric bearing, 130: housing, 130c: side surface, 131 ... recess, 133 ... liquid chamber, 140 ... electronic control unit (ECU), 161 ... accommodation chamber (pump chamber), 170 ... suction valve, 180 ... discharge valve, 181 ... Valve, 183 ... Spring, 185 ... Cover member (flow path forming member), 185a ... Spring chamber, 187 ... Path

Claims (4)

A brake fluid pressure control device (20) for controlling a fluid pressure of a brake fluid pressure circuit,
A housing (130) having a brake fluid passage formed therein;
A motor (96) mounted on the housing (130);
A plurality of pump elements (44) mounted in a recess (131) formed in a side surface of the housing (130) and driven by the motor (96);
The pump element (44)
A suction valve (170) for sucking brake fluid into the pump chamber (161),
A discharge valve (180) for discharging brake fluid from the pump chamber (161),
A flow path forming member (185) disposed on the discharge side of the discharge valve (180);
The flow path forming member (185) includes:
A spring chamber (185a) accommodating a spring (183) for urging the valve element (181) of the discharge valve (180) in a valve closing direction;
A passage (187) communicating the spring chamber (185a) with an outer surface of the flow path forming member (185);
The passage (187) of the flow path forming member (185) of each of the plurality of pump elements (44) is
The brake fluid pressure control device, which extends upward from a position including the uppermost portion in the vertical direction of the spring chamber (185a) and is connected to the outer surface. When the flow path forming member (185) is viewed in the axial direction,
The brake fluid pressure control device according to claim 1, wherein the uppermost portion in the vertical direction of the spring chamber (185a) is located between left and right boundary lines (L1, L2) of the passage (187). When the flow path forming member (185) is viewed in the axial direction,
The brake fluid pressure control device according to claim 1 or 2, wherein the passage (187) extends vertically upward from the spring chamber (185a). When the flow path forming member (185) is viewed in the axial direction,
The passage (187) extends upward from a vertically upper portion while being inclined to one of the left and right sides.
The width (W) of the passage (187), the radius (r) of the spring chamber (185a), and the inclination angle (θ) of the passage (187) are expressed by the following equation (1).

The brake fluid pressure control device according to claim 1 or 2, wherein:

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